Plain English Summary
Background and study aims
Recent studies suggest that dairy may affect the body in different ways depending on the form in which it is eaten. This study will examine the effect of dairy fat, in three different forms (presented in three different food types) on how much lipid (fat) is present in the blood, and other aspects of metabolic health (for example, the amount of energy used by the body, or how substances are broken down/made in the body). This study aims to improve understanding about how fats are processed in the body.
Who can participate?
Healthy adults, between the ages of 50-70, with a BMI of over 25kg/m2, and not on a prescribed diet.
What does the study involve?
At the start of the study, all participants attend the UCD volunteer suites for an assessment. This includes them having a fasting blood sample and body measurements taken. They also have their diet assessed by a trained nutritionist, involving the completion of a questionnaire on that they eat and when and what they have eaten the day the day before. The participants are then randomly allocated into one of four groups and are given their test foods, on portioned packs with instructions on how to eat them, for the next 6 weeks. Those in group one are given dairy fat in the form of regular fat cheese. Those in group two are given dairy fat in the form of reduced fat cheese plus butter. Those in group three are given dairy fat in the form of butter alone. Those in group four are controls and are asked to limit dairy intake to very small amounts, but to otherwise maintain their normal diet. During the 6 weeks of the study, all participants are asked to complete more dietary assessments over the phone with a nutritionist and also to record whether they have stuck to the diet or not. At the end of the 6 weeks, the participants return to the volunteer suites, and complete the same tests as they did at the beginning of the study. A random selection of people are then asked to do a ‘metabolic challenge’ test. They are given a high fat food to eat. Blood samples are then taken over the next 5 hours to monitor how quickly their body responds to the challenge. A small cannula, like a small tap, is inserted into the vein to avoid multiple pricks for blood tests. The participants are given more food to eat after the test.
What are the possible benefits and risks of participating?
There are no known benefits of taking part. However, those who take part will be contributing to research. There may be some slight discomfort upon the blood samples but it will be conducted by trained experienced professionals and will only consist of a small amount of blood taken (less than a blood donation). There are no other known risks associated with taking part in this study.
Where is the study run from?
UCD Institute of Food and Health (Ireland)
When is the study starting and how long is it expected to run for?
September 2015 to December 2016
Who is funding the study?
Food for Health Ireland (Ireland)
Who is the main contact?
Dr Emma Feeney
Dr Emma Feeney
UCD School of Agriculture & Food Science
Institute of Food and Health
Science Centre - South
University College Dublin
The effect of dairy fat on metabolic health - understanding the 'matrix' effect of cheese
To establish whether the form (matrix) in which dairy fat is consumed has an effect on parameters of metabolic health
University College Dublin Human Research Ethics Committee, 31/07/15, ref: LS-15-44-Feeney-Gibney
Single-centre intervention study
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Participants will be randomised into one of four groups, each receiving dairy fat in different forms:
Group 1: To receive dairy fat in the form of regular fat cheese
Group 2: To receive dairy fat in the form of reduced fat cheese plus butter
Group 3: To receive dairy fat in the form of butter alone
Group 4: A control group asked to limit dairy intake to very small amounts, to consume no cheese/cheese products during the wash out period and to maintain habitual diet throughout the 6 week intervention period
A subset of subjects from each group will then undergo a metabolic challenge in which high fat food is consumed, blood lipid profiles are measured over a course of four hours.
Primary outcome measure
Fasting blood markers of metabolic health following 6 weeks daily consumption of dairy fat, in 3 different matrices.
A subset of subjects (n=24) will give multiple blood samples (8 in total) over 5 hours. Analysis will be performed at all time points.
Secondary outcome measures
Postprandial blood-lipid and glucose following an oral lipid challenge in a subset of subjects.
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Healthy, on no medication
2. Not following a prescribed diet for any reason (weight loss, cholesterol etc)
3. Male or female, aged between 50-70
4. BMI >25 kg/m2
Target number of participants
Participant exclusion criteria
1. Outside the specified age
2. BMI <25 kg/m2
3. Anyone who is currently taking prescribed medication for cholesterol-reduction purposes
4. Anyone following any specific diet to control or modify their cholesterol or weight
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
University College Dublin Institute of Food and Health
University College Dublin School of Agriculture & Food Science Science Centre - South University College Dublin Belfield
Food for Health Ireland
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Publications planned to include (but not limited to):
1. Changes in anthropometry (if any) following 6 weeks of different diets
2. Changes in blood lipid markers
3. Changes in fasting glucose/insulin levels
A further publication will examine postprandial responses to a lipid tolerance test , before and after 6 weeks consumption of the different diets.
Publications are planned for submission to high impact clinical nutrition journals.
Intention to publish date
Participant level data
Not expected to be available
Basic results (scientific)
2018 results in: https://www.ncbi.nlm.nih.gov/pubmed/30107488